1. Field of the Invention
The present invention generally relates a light source module; particularly, the present invention relates a light source module which can decrease the cost and increase the brightness.
2. Description of the Prior Art
As shown in FIG. 1, FIG. 1 is a schematic view of a conventional light source module, wherein a light source unit 2A and a light source unit 2B are disposed on a substrate 3. Each of the light source units 2A and 2B has a width W and a spacing G exists between the light source units 2A and 2B. The pitch P of the light source unit 2A and the light source unit 2B is a distance between an edge 21A of the light source unit 2A and an edge 21B of the light source unit 2B. The pitch P can also refer to a sum of the width W and the spacing G. It is noted that the spacing G represents a width allowing the disposition of a layout area between the light source unit 2A and the light source unit 2B. The amount of the light source units allowed to be disposed on the substrate can be directly estimated from a relation between the length of the substrate 3 and the pitch P of the adjacent light source units. In addition, a positive electrode end and a negative electrode end of the light source unit 2A are respectively connected with a pad 4 and a pad 5; a positive electrode end and a negative electrode end of the light source unit 2B are respectively connected with a pad 6 and a pad 7.
It is noted that the pads are connected with a circuit (not shown) through the conducting wires 8. Particularly, the R&D people need to reserve the spacing between the adjacent light source units on the substrate 3 for the layout of the conducting wires 8. As shown in FIG. 1, the conducting wire 8 on the substrate 3 has a wire space width L. In practical applications, there is a gap between adjacent conducting wires 8 (i.e. the wire has a certain distance to the adjacent wire) for avoiding the noise. The wire space width L is a major factor to influence the magnitude of the pitch P. However, in the present design structure, it is difficult to decrease the width of the conducting wire 8 and the spacing between adjacent conducting wires, so that the pitch P is difficult to be decreased. Particularly, in the case that the substrate 3 has a given area, the increase in amount of light source units is limited, so that the overall brightness of the light source is restricted. In addition, the conducting wire 8 connected with the pad 5 has a negative electrical signal, and the conducting wire 8 connected with the pad 6 has a positive electrical signal, so the two conducting wires 8 cannot share a common wire. As a result, the pitch P cannot be further decreased.
For instance, the length of the light source module for a 10-inch tablet is about 216.81 mm. If the width W of the light source unit is 3.8 mm and the spacing G is 1.5 mm (i.e. the pitch P is 5.3 mm), the amount of light source units allowed to be arranged is merely about 40. In addition, if the width W of the light source unit is 2.8 mm and the spacing G is 1.8 mm (i.e. the pitch P is 4.6 mm), the amount of light source units allowed to be arranged is merely about 48. In these two cases, the amount of light source units is insufficient to increase the brightness, and the overall brightness of the light source module cannot be increased.